Exemplary embodiments herein relate to a seat assembly for a vehicle, and more particularly, to a rotational damper for a vehicle seat assembly configured to vary the torque as a seat base is moved between a seated position and a stowed position.
Many sedans, coupes, CUVs, and SUVs have rear-folding seats and/or fold-and-tumble seats. Such rear seats include a seat base and a seatback pivotally connected to the seat base. The seatback can be moved from an upright, seated position to a folded position where the seatback is generally parallel to the seat base. The seat base can be moved from a seated position, and together with the folded seatback, to a stowed position. In the stowed position, the seat base and seatback are disposed generally parallel to each other, and also generally perpendicular or generally parallel to the vehicle floor.
Rear-folding seats also typically include a rotational damper associated with the seat base to dampen the movement of the seat base from the seated position to the stowed position. This known rotational damper generally has the same torque value for multiple revolutions in both directions of rotation. More particularly, the known rotational damper includes a housing defining a chamber for holding therein a viscous fluid. Disc-shaped fins are rotationally supported within the housing chamber. The chamber is uniform such that the torque values are approximately the same in both directions of rotation. Therefore, with this construction, the conventional rotational damper operates within one revolution range and cannot provide variable torque values to the seat assembly as the seat base is being moved from the seated position to the stowed position. This can cause the seat base and seatback to fall towards the stowed position or back toward the seated position at an undesirable rate depending on whether the stowed position is generally parallel or perpendicular to the vehicle floor.